基于磁共振成像新技术的颅内动脉粥样硬化狭窄高危患者斑块性质与血流变化导致卒中复发的机制研究

The patients with high risk intracranial atherosclerotic atherosclerosis (ICAS) are those with symptomatic 70%-99% stenosis and qualifying event within 30 days enrollment. For these patients, the recurrent stroke rate remains high. By now the mechanisms of recurrent stroke in patients with high risk ICAS are related to plaque vulnerability and low compensatory blood level, but by now there has not a one-stop imaging modality to clarify these mechanisms. Based on the previous successfully three-dimensional volume imaging for plaque and territory perfusion imaging for collateral perfusion, this study focusing on patients with high risk ICAS, combining the recurrent strokes after aggressive medical treatment, try to identify plaque characteristics including distribution, burden, composition, and enhancement with thrombosis, artery to artery embolism, and perforator event, and to evaluate change of cerebral blood flow provided by collateral perfusion with distal hypoperfusion. This study will clarify the mechanisms of plaque characteristics and compensatory blood flow changes by collateral related to recurrent stroke in patients with high risk ICAS based on new magnetic resonance imaging technologies, and establish predictors of recurrent stroke in patients with high risk ICAS for selection of target population in sequential clinical trials, and that will lower risk of recurrent stroke in this cohorts.

颅内动脉粥样硬化性狭窄（ICAS）高危患者是指末次发病30天内狭窄程度70%-99%的症状性患者，此类患者存在卒中复发率高、易遗留后遗症的特点。研究显示ICAS高危患者卒中复发与易损斑块和侧枝代偿不良有关，但目前缺乏一站式影像学检查模式研究上述关系。我们前期成功研发了磁共振三维容积斑块成像技术和分区灌注成像技术，本研究拟利用此技术针对ICAS高危患者，结合强化药物治疗后的卒中复发情况，研究①斑块分布、负荷、组分及强化等斑块形态学特征与血栓形成、动脉到动脉栓塞、穿支动脉受累的关系；②狭窄远端侧枝灌注脑血流量变化与狭窄远端低灌注的关系。确立基于影像学基础的ICAS高危患者斑块性质与侧枝灌注血流变化导致卒中复发的机制，同时为后续分层治疗研究筛选预警指标，最终降低相关脑血管病卒中复发率。

国人33%-50%的缺血性卒中系颅内动脉粥样硬化性狭窄（Intracranial atherosclerotic stenosis, ICAS）所致。本课题通过：1）研究高分辨磁共振下ICAS斑块和供血区域侧枝灌注成像的相关性；2）研究症状性ICAS高危患者的斑块特点（斑块分布、斑块负荷、重构情况、强化方式、组分分析）；3)入组患者行强化内科药物治疗，并进行1年的随访了解卒中复发情况；4）研究斑块和侧枝灌注与随访期内卒中复发的相关性。目前已发现后循环血管内治疗组：术前高分辨核磁下责任斑块的某些特征与术后30天并发症发生情况之间有一定联系，为建立ICAS行血管内治疗的高危并发症人群筛选流程，更好推广血管内治疗手段以降低相关卒中复发率，推动ICAS卒中二级预防体系的构建作出了贡献，并可产生较大的社会和经济效益。